An on-demand shared tree with hybrid state for multicast routing in ad hoc mobile wireless networks

This paper describes the multicast shared tree protocol (MSTP) that has been designed to support the delivery of multicast packets in a mobile ad hoc network. MSTP uses a shared tree as its basic multicast infrastructure and, to maintain the tree against topology changes and network failures, it adopts the so called hybrid-state reliability mechanism, which combines the use of soft and hard state mechanisms applied to an on-demand scheme. It ensures fault tolerance and high group connectivity despite mobility, and provides a light-weight tree maintenance procedure.